Today, human beings have obtained a large amount of energy mainly from oil, coal, nuclear energy, natural gas, etc. but energy sources such as coal and nuclear energy are expected to be exhausted in the near future. Thus, countries of the world have accelerated research and development of new renewable energy. Particularly, solar generation has drawn much attention, since electric power can be obtained from any sunlit place and does not generate pollution unlike other generation methods.
For solar generation, a semiconductor device that converts solar energy into electrical energy is needed. The semiconductor device is referred to as a solar cell. In general, since a maximum voltage that can be generated by only one unit solar cell is about 0.5 V, a plurality of unit solar cells connected in series should be used. A structure in which unit solar cells are modularized by connecting them to one another is referred to as a solar cell module.
A process of manufacturing a solar cell module may be divided into a cell test process, a tabbing process, a lay-up process, a lamination process, and a module test process.
In the first process, i.e., the cell test process, a plurality of solar cells having various electric properties are tested and classified into several groups according to their electric properties. In the second process, i.e., the tabbing process, the plurality of solar cells are connected in series by wires. In the third process, i.e., the lay-up process, the plurality of solar cells that are connected in a line are arranged in a desired pattern and then low-iron reinforced glass, ethylene-vinyl acetate copolymer (EVA), a back sheet, etc. are stacked on them. In the fourth process, i.e., the lamination process, a resultant structure obtained in the form of a solar cell module by performing the lay-up process is vacuum-compressed at a high temperature to provide durability and a waterproof property. In the last process, i.e., the module test process, the finished solar cell module is tested for normal operation.
Here, the tabbing process in which the plurality of solar cells are connected in series by wires is a key process with respect to the process of manufacturing a solar cell module. When the wires are not appropriately bonded to the cells, the performance and quality of the whole solar cell module are degraded. The tabbing process will be briefly described below. A plurality of wires supplied from a reel are cut. Then, the wires and solar cells are exposed to a high-temperature atmosphere while repeating that one side of each wire is placed on a solar cell to lie on the cell and another solar cell is placed and stacked on the opposite side of each wire. In the high-temperature atmosphere, the wires are soldered onto the cells, and thus, the plurality of solar cells are electrically connected by the wires.
The background technology of the present invention is disclosed in Korean registered patent publication No. 10-1058399 entitled “Tabber-Stringer and Tabbing-Stringing Method” (registration date: Aug. 16, 2011).